Radiation arrangements such as lasers and/or light sources, for example, are realized nowadays in a manner occupying an extremely small space. By way of example, it is known to form radiation arrangements in a manner similar to a microchip in large numbers on a wafer. The radiation arrangements formed on the wafer can be singulated, in which case each of the radiation arrangements can respectively have for example one, two or more lasers and/or light sources. As the dimensions of the radiation arrangements become smaller, however, problems increasingly occur. By way of example, unavoidable component tolerances become more and more dominant in comparison with the overall dimensions of the radiation arrangements. At the same time it becomes more and more difficult to align the extremely small components precisely with respect to one another. Consequently, it becomes more and more difficult to obtain precisely placed emission points in the radiation arrangements, which is of great importance, however, exactly in the case of radiation arrangements for high-precision applications. This may have the effect, for example, that a high level of rejects are produced during the production of the radiation arrangements for high-precision applications.
By way of example, the use of laser pico-projector modules in mobile terminals, for example in cellular phones, makes stringent requirements of the laser module (laser and optical unit) with regard to structural size, efficiency, image quality and costs. A particular challenge is posed here by the required image quality, which can be achieved only by high-precision arrangement of the laser source and the optical elements on the substrate used and with respect to one another. Such precision mounting can be impeded by inherent component fluctuations, for example. The high precision to be achieved for the arrangement whilst at the same time maintaining the possibility of manufacture in large numbers requires, in principle, a special module construction concept.
Optical requirements may demand, for example, that the radiation coupled out from an RGB laser module is collimatable, combinable and/or polarizable, for example circularly polarizable. The objectives of collimation and circular polarizability, in particular, lead in part to requirements made of the alignment accuracy of the optical elements and lasers in the micrometers range or below that. The collimation and/or combination can make stringent requirements of accuracy for example since the collimated combined beams can be directed for example onto a scanning device, which can represent a bottleneck in the beam path of the coupled-out electromagnetic radiation.
Manufacturing-dictated fluctuations of the geometrical dimensions of the lasers, for example with regard to the substrate thickness of the substrates used, prevent simple planar mounting of lasers and optical unit in the known production methods. In these methods, an additional alignment perpendicular to the surface of the substrate used always has to be effected as well, which is solved for example by applying adhesives and/or solders with different thicknesses. This vastly increases the complexity of the alignment process and, in particular, of the joining method, and can be carried out precisely only with high outlay.
A further requirement may be that lasers have to be operated in a hermetically protected atmosphere, since otherwise some lasers are subject to a high degree of wear.